SoXt is an open source implementation of the SGI InventorXt library,
which is a GUI binding for using Open Inventor with Xt/Motif. While
SoXt has been developed for use with Coin, it is also possible to
compile it against Open Inventor from SGI or TGS. A goal is to
eventually become 100% source code compatible with the InventorXt
library, which is still way off, especially when it comes to creating
derived classes.
When using SoXt, bear in mind that SoXt is in its alpha release
phase, so expect the worst...
WWW: https://bitbucket.org/Coin3D/coin/wiki/Home

When linking a library libA with a library libB using libtool, if libB.la
exists, libtool will add all libraries libB.la refers to (dependency_libs
field) to the linker command line and store them in the dependency_libs
field of libA.la. So everything that subsequently links with libA will also
link to these extra libraries. This causes too much overlinking.
This commit modifies Mk/Uses/libtool.mk so it empties the dependency_libs
field in .la libraries during staging. However, because .la libraries have
very limited use when dependency_libs is empty it makes sense to completely
remove them during staging.
So with this commit USES=libtool is modified to remove .la libraries and a
new form (USES=libtool:keepla) is introduced in case they need to be kept
(dependency_libs is still emptied).

This changes almost all the "gnomehack" only USE_GNOME cases to USES= pathfix.
If a port used other USE_GNOME items it was untouched.
The ports that used other USES were fixed by hand.
PR: ports/177081
Reviewed by: bapt
Approved by: portmgr (miwi)

Update CONFIGURE_ARGS for how we pass CONFIGURE_TARGET to configure script.
Specifically, newer autoconf (> 2.13) has different semantic of the
configure target. In short, one should use --build=CONFIGURE_TARGET
instead of CONFIGURE_TARGET directly. Otherwise, you will get a warning
and the old semantic may be removed in later autoconf releases.
To workaround this issue, many ports hack the CONFIGURE_TARGET variable
so that it contains the ``--build='' prefix.
To solve this issue, under the fact that some ports still have
configure script generated by the old autoconf, we use runtime detection
in the do-configure target so that the proper argument can be used.
Changes to Mk/*:
- Add runtime detection magic in bsd.port.mk

Mass-conversion to the USE_AUTOTOOLS New World Order. The code present
in bsd.autotools.mk essentially makes this a no-op given that all the
old variables set a USE_AUTOTOOLS_COMPAT variable, which is parsed in
exactly the same way as USE_AUTOTOOLS itself.
Moreover, USE_AUTOTOOLS has already been extensively tested by the GNOME
team -- all GNOME 2.12.x ports use it.
Preliminary documentation can be found at:
http://people.FreeBSD.org/~ade/autotools.txt
which is in the process of being SGMLized before introduction into the
Porters Handbook.
Light blue touch-paper. Run.

Whoa there, boy, that's a mighty big commit y'all have there...
Begin autotools sanitization sequence by requiring ports to explicitly
specify which version of {libtool,autoconf,automake} they need, erasing
the concept of a "system default".
For ports-in-waiting:
USE_LIBTOOL=YES -> USE_LIBTOOL_VER=13
USE_AUTOCONF=YES -> USE_AUTOCONF_VER=213
USE_AUTOMAKE=YES -> USE_AUTOMAKE_VER=14
Ports attempting to use the old style system after June 1st 2004 will be
sorely disappointed.